/**
 * @author mr.doob / http://mrdoob.com/
 * @author kile / http://kile.stravaganza.org/
 * @author alteredq / http://alteredqualia.com/
 * @author mikael emtinger / http://gomo.se/
 * @author zz85 / http://www.lab4games.net/zz85/blog
 */

GLE.Geometry = function () {

	this.id = GLE.GeometryCount ++;

	this.vertices = [];
	this.colors = []; // one-to-one vertex colors, used in ParticleSystem, Line and Ribbon

	this.materials = [];

	this.faces = [];

	this.faceUvs = [[]];
	this.faceVertexUvs = [[]];

	this.morphTargets = [];
	this.morphColors = [];
	this.morphNormals = [];

	this.skinWeights = [];
	this.skinIndices = [];

	this.boundingBox = null;
	this.boundingSphere = null;

	this.hasTangents = false;

	this.dynamic = false; // unless set to true the *Arrays will be deleted once sent to a buffer.

};

GLE.Geometry.prototype = {

	constructor : GLE.Geometry,

	applyMatrix: function ( matrix ) {

		var matrixRotation = new GLE.Matrix4();
		matrixRotation.extractRotation( matrix );

		for ( var i = 0, il = this.vertices.length; i < il; i ++ ) {

			var vertex = this.vertices[ i ];

			matrix.multiplyVector3( vertex.position );

		}

		for ( var i = 0, il = this.faces.length; i < il; i ++ ) {

			var face = this.faces[ i ];

			matrixRotation.multiplyVector3( face.normal );

			for ( var j = 0, jl = face.vertexNormals.length; j < jl; j ++ ) {

				matrixRotation.multiplyVector3( face.vertexNormals[ j ] );

			}

			matrix.multiplyVector3( face.centroid );

		}

	},

	computeCentroids: function () {

		var f, fl, face;

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];
			face.centroid.set( 0, 0, 0 );

			if ( face instanceof GLE.Face3 ) {

				face.centroid.addSelf( this.vertices[ face.a ].position );
				face.centroid.addSelf( this.vertices[ face.b ].position );
				face.centroid.addSelf( this.vertices[ face.c ].position );
				face.centroid.divideScalar( 3 );

			} else if ( face instanceof GLE.Face4 ) {

				face.centroid.addSelf( this.vertices[ face.a ].position );
				face.centroid.addSelf( this.vertices[ face.b ].position );
				face.centroid.addSelf( this.vertices[ face.c ].position );
				face.centroid.addSelf( this.vertices[ face.d ].position );
				face.centroid.divideScalar( 4 );

			}

		}

	},

	computeFaceNormals: function () {

		var n, nl, v, vl, vertex, f, fl, face, vA, vB, vC,
		cb = new GLE.Vector3(), ab = new GLE.Vector3();

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			vA = this.vertices[ face.a ];
			vB = this.vertices[ face.b ];
			vC = this.vertices[ face.c ];

			cb.sub( vC.position, vB.position );
			ab.sub( vA.position, vB.position );
			cb.crossSelf( ab );

			if ( !cb.isZero() ) {

				cb.normalize();

			}

			face.normal.copy( cb );

		}

	},

	computeVertexNormals: function () {

		var v, vl, f, fl, face, vertices;

		// create internal buffers for reuse when calling this method repeatedly
		// (otherwise memory allocation / deallocation every frame is big resource hog)

		if ( this.__tmpVertices === undefined ) {

			this.__tmpVertices = new Array( this.vertices.length );
			vertices = this.__tmpVertices;

			for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

				vertices[ v ] = new GLE.Vector3();

			}

			for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

				face = this.faces[ f ];

				if ( face instanceof GLE.Face3 ) {

					face.vertexNormals = [ new GLE.Vector3(), new GLE.Vector3(), new GLE.Vector3() ];

				} else if ( face instanceof GLE.Face4 ) {

					face.vertexNormals = [ new GLE.Vector3(), new GLE.Vector3(), new GLE.Vector3(), new GLE.Vector3() ];

				}

			}

		} else {

			vertices = this.__tmpVertices;

			for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

				vertices[ v ].set( 0, 0, 0 );

			}

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			if ( face instanceof GLE.Face3 ) {

				vertices[ face.a ].addSelf( face.normal );
				vertices[ face.b ].addSelf( face.normal );
				vertices[ face.c ].addSelf( face.normal );

			} else if ( face instanceof GLE.Face4 ) {

				vertices[ face.a ].addSelf( face.normal );
				vertices[ face.b ].addSelf( face.normal );
				vertices[ face.c ].addSelf( face.normal );
				vertices[ face.d ].addSelf( face.normal );

			}

		}

		for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			vertices[ v ].normalize();

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			if ( face instanceof GLE.Face3 ) {

				face.vertexNormals[ 0 ].copy( vertices[ face.a ] );
				face.vertexNormals[ 1 ].copy( vertices[ face.b ] );
				face.vertexNormals[ 2 ].copy( vertices[ face.c ] );

			} else if ( face instanceof GLE.Face4 ) {

				face.vertexNormals[ 0 ].copy( vertices[ face.a ] );
				face.vertexNormals[ 1 ].copy( vertices[ face.b ] );
				face.vertexNormals[ 2 ].copy( vertices[ face.c ] );
				face.vertexNormals[ 3 ].copy( vertices[ face.d ] );

			}

		}

	},

	computeMorphNormals: function () {

		var i, il, f, fl, face;

		// save original normals
		// - create temp variables on first access
		//   otherwise just copy (for faster repeated calls)

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			if ( ! face.__originalFaceNormal ) {

				face.__originalFaceNormal = face.normal.clone();

			} else {

				face.__originalFaceNormal.copy( face.normal );

			}

			if ( ! face.__originalVertexNormals ) face.__originalVertexNormals = [];

			for ( i = 0, il = face.vertexNormals.length; i < il; i ++ ) {

				if ( ! face.__originalVertexNormals[ i ] ) {

					face.__originalVertexNormals[ i ] = face.vertexNormals[ i ].clone();

				} else {

					face.__originalVertexNormals[ i ].copy( face.vertexNormals[ i ] );

				}

			}

		}

		// use temp geometry to compute face and vertex normals for each morph

		var tmpGeo = new GLE.Geometry();
		tmpGeo.faces = this.faces;

		for ( i = 0, il = this.morphTargets.length; i < il; i ++ ) {

			// create on first access

			if ( ! this.morphNormals[ i ] ) {

				this.morphNormals[ i ] = {};
				this.morphNormals[ i ].faceNormals = [];
				this.morphNormals[ i ].vertexNormals = [];

				var dstNormalsFace = this.morphNormals[ i ].faceNormals;
				var dstNormalsVertex = this.morphNormals[ i ].vertexNormals;

				var faceNormal, vertexNormals;

				for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

					face = this.faces[ f ];

					faceNormal = new GLE.Vector3();

					if ( face instanceof GLE.Face3 ) {

						vertexNormals = { a: new GLE.Vector3(), b: new GLE.Vector3(), c: new GLE.Vector3() };

					} else {

						vertexNormals = { a: new GLE.Vector3(), b: new GLE.Vector3(), c: new GLE.Vector3(), d: new GLE.Vector3() };

					}

					dstNormalsFace.push( faceNormal );
					dstNormalsVertex.push( vertexNormals );

				}

			}

			var morphNormals = this.morphNormals[ i ];

			// set vertices to morph target

			tmpGeo.vertices = this.morphTargets[ i ].vertices;

			// compute morph normals

			tmpGeo.computeFaceNormals();
			tmpGeo.computeVertexNormals();

			// store morph normals

			var faceNormal, vertexNormals;

			for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

				face = this.faces[ f ];

				faceNormal = morphNormals.faceNormals[ f ];
				vertexNormals = morphNormals.vertexNormals[ f ];

				faceNormal.copy( face.normal );

				if ( face instanceof GLE.Face3 ) {

					vertexNormals.a.copy( face.vertexNormals[ 0 ] );
					vertexNormals.b.copy( face.vertexNormals[ 1 ] );
					vertexNormals.c.copy( face.vertexNormals[ 2 ] );

				} else {

					vertexNormals.a.copy( face.vertexNormals[ 0 ] );
					vertexNormals.b.copy( face.vertexNormals[ 1 ] );
					vertexNormals.c.copy( face.vertexNormals[ 2 ] );
					vertexNormals.d.copy( face.vertexNormals[ 3 ] );

				}

			}

		}

		// restore original normals

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			face.normal = face.__originalFaceNormal;
			face.vertexNormals = face.__originalVertexNormals;

		}

	},

	computeTangents: function () {

		// based on http://www.terathon.com/code/tangent.html
		// tangents go to vertices

		var f, fl, v, vl, i, il, vertexIndex,
			face, uv, vA, vB, vC, uvA, uvB, uvC,
			x1, x2, y1, y2, z1, z2,
			s1, s2, t1, t2, r, t, test,
			tan1 = [], tan2 = [],
			sdir = new GLE.Vector3(), tdir = new GLE.Vector3(),
			tmp = new GLE.Vector3(), tmp2 = new GLE.Vector3(),
			n = new GLE.Vector3(), w;

		for ( v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			tan1[ v ] = new GLE.Vector3();
			tan2[ v ] = new GLE.Vector3();

		}

		function handleTriangle( context, a, b, c, ua, ub, uc ) {

			vA = context.vertices[ a ].position;
			vB = context.vertices[ b ].position;
			vC = context.vertices[ c ].position;

			uvA = uv[ ua ];
			uvB = uv[ ub ];
			uvC = uv[ uc ];

			x1 = vB.x - vA.x;
			x2 = vC.x - vA.x;
			y1 = vB.y - vA.y;
			y2 = vC.y - vA.y;
			z1 = vB.z - vA.z;
			z2 = vC.z - vA.z;

			s1 = uvB.u - uvA.u;
			s2 = uvC.u - uvA.u;
			t1 = uvB.v - uvA.v;
			t2 = uvC.v - uvA.v;

			r = 1.0 / ( s1 * t2 - s2 * t1 );
			sdir.set( ( t2 * x1 - t1 * x2 ) * r,
					  ( t2 * y1 - t1 * y2 ) * r,
					  ( t2 * z1 - t1 * z2 ) * r );
			tdir.set( ( s1 * x2 - s2 * x1 ) * r,
					  ( s1 * y2 - s2 * y1 ) * r,
					  ( s1 * z2 - s2 * z1 ) * r );

			tan1[ a ].addSelf( sdir );
			tan1[ b ].addSelf( sdir );
			tan1[ c ].addSelf( sdir );

			tan2[ a ].addSelf( tdir );
			tan2[ b ].addSelf( tdir );
			tan2[ c ].addSelf( tdir );

		}

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];
			uv = this.faceVertexUvs[ 0 ][ f ]; // use UV layer 0 for tangents

			if ( face instanceof GLE.Face3 ) {

				handleTriangle( this, face.a, face.b, face.c, 0, 1, 2 );

			} else if ( face instanceof GLE.Face4 ) {

				handleTriangle( this, face.a, face.b, face.c, 0, 1, 2 );
				handleTriangle( this, face.a, face.b, face.d, 0, 1, 3 );

			}

		}

		var faceIndex = [ 'a', 'b', 'c', 'd' ];

		for ( f = 0, fl = this.faces.length; f < fl; f ++ ) {

			face = this.faces[ f ];

			for ( i = 0; i < face.vertexNormals.length; i++ ) {

				n.copy( face.vertexNormals[ i ] );

				vertexIndex = face[ faceIndex[ i ] ];

				t = tan1[ vertexIndex ];

				// Gram-Schmidt orthogonalize

				tmp.copy( t );
				tmp.subSelf( n.multiplyScalar( n.dot( t ) ) ).normalize();

				// Calculate handedness

				tmp2.cross( face.vertexNormals[ i ], t );
				test = tmp2.dot( tan2[ vertexIndex ] );
				w = (test < 0.0) ? -1.0 : 1.0;

				face.vertexTangents[ i ] = new GLE.Vector4( tmp.x, tmp.y, tmp.z, w );

			}

		}

		this.hasTangents = true;

	},

	computeBoundingBox: function () {

		if ( ! this.boundingBox ) {

			this.boundingBox = { min: new GLE.Vector3(), max: new GLE.Vector3() };

		}

		if ( this.vertices.length > 0 ) {

			var position, firstPosition = this.vertices[ 0 ].position;

			this.boundingBox.min.copy( firstPosition );
			this.boundingBox.max.copy( firstPosition );

			var min = this.boundingBox.min,
				max = this.boundingBox.max;

			for ( var v = 1, vl = this.vertices.length; v < vl; v ++ ) {

				position = this.vertices[ v ].position;

				if ( position.x < min.x ) {

					min.x = position.x;

				} else if ( position.x > max.x ) {

					max.x = position.x;

				}

				if ( position.y < min.y ) {

					min.y = position.y;

				} else if ( position.y > max.y ) {

					max.y = position.y;

				}

				if ( position.z < min.z ) {

					min.z = position.z;

				} else if ( position.z > max.z ) {

					max.z = position.z;

				}

			}

		} else {

			this.boundingBox.min.set( 0, 0, 0 );
			this.boundingBox.max.set( 0, 0, 0 );

		}

	},

	computeBoundingSphere: function () {

		if ( ! this.boundingSphere ) this.boundingSphere = { radius: 0 };

		var radius, maxRadius = 0;

		for ( var v = 0, vl = this.vertices.length; v < vl; v ++ ) {

			radius = this.vertices[ v ].position.length();
			if ( radius > maxRadius ) maxRadius = radius;

		}

		this.boundingSphere.radius = maxRadius;

	},

	/*
	 * Checks for duplicate vertices with hashmap.
	 * Duplicated vertices are removed
	 * and faces' vertices are updated.
	 */

	mergeVertices: function() {

		var verticesMap = {}; // Hashmap for looking up vertice by position coordinates (and making sure they are unique)
		var unique = [], changes = [];

		var v, key;
		var precisionPoints = 4; // number of decimal points, eg. 4 for epsilon of 0.0001
		var precision = Math.pow( 10, precisionPoints );
		var i,il, face;

		for ( i = 0, il = this.vertices.length; i < il; i ++ ) {

			v = this.vertices[ i ].position;
			key = [ Math.round( v.x * precision ), Math.round( v.y * precision ), Math.round( v.z * precision ) ].join( '_' );

			if ( verticesMap[ key ] === undefined ) {

				verticesMap[ key ] = i;
				unique.push( this.vertices[ i ] );
				changes[ i ] = unique.length - 1;

			} else {

				//console.log('Duplicate vertex found. ', i, ' could be using ', verticesMap[key]);
				changes[ i ] = changes[ verticesMap[ key ] ];

			}

		};


		// Start to patch face indices

		for( i = 0, il = this.faces.length; i < il; i ++ ) {

			face = this.faces[ i ];

			if ( face instanceof GLE.Face3 ) {

				face.a = changes[ face.a ];
				face.b = changes[ face.b ];
				face.c = changes[ face.c ];

			} else if ( face instanceof GLE.Face4 ) {

				face.a = changes[ face.a ];
				face.b = changes[ face.b ];
				face.c = changes[ face.c ];
				face.d = changes[ face.d ];

			}

		}

		// Use unique set of vertices

		this.vertices = unique;

	}

};

GLE.GeometryCount = 0;
